Loss of sight has been a major disorder associated with progressive neurodegenerative disorder involving motor and cognitive dysfunction. Currently, there is no effective treatment either for symptomatic relief or disease modification. This relates, in part, to a lack of knowledge of the underlying neurochemical abnormalities, including cholinergic neurons status in the diffused system of the visual relay centres. To determine histologically the possible adopted mode of cell death in the visual relay centres, previous studies have shown difference in cell death based on treatment dosage and location in brain. 50 F1 generation adult Wistar rats were treated with potassium hexacyanoferrate for a period of 30 days and the tissues were processed histologically (Hematoxylin and eosin, Gordon and sweets and crystal violet) to determine the cellular changes and characterize as apoptotic or necrotic. The predominant mode of cell death in the V1 is apoptosis while necrotic tissue sites were found to exist in the superior colliculus (SC) of the same treatment, certain cells in the lateral geniculate body (LGB) showed morphological features of both apoptosis and necrosis.

Key words: Cyanide, toxicity, visual relay centres, cell death, necrosis, apoptosis.